In vitro activity of new quinoxaline compounds against Campylobacter species and Clostridium difficile

SC-44914 and SC-44942-A are two new quinoxaline compounds with a spectrum of activity similar to that of metronidazole. We studied the activity of SC-44914 and SC-44942-A against 35 Campylobacter jejuni, 30 C. coli, and 20 Clostridium (Cl.) difficile and compared it with that of metronidazole by utilizing an agar dilution method. The quinoxalines had little activity against the C. jejuni and C. coli [minimum inhibitory concentration (MIC)90 > or = 64 micrograms/ml]. SC-44914 and SC-44942-A had excellent activity against Cl. difficile (MIC90 < or = 0.06 micrograms/ml for SC 44914, and 0.5 micrograms/ml for SC-44942A).